Hello everyone,
We currently have a problem in connection with auto responses.
Our mail system changes the sender address for auto responses and adds the String "no-reply=31=" at the beginning of the address. The number in this string is random. The SMTP-log from our mailsystem says: 5.5.1 Incorrect command sequence.
It looks like Sophos is not accepting this sender address, but unfortunately I don't see any logs.
The way I can explain this is that by changing the sender address, Sophos recognizes that this mailbox does not exist and discards the mail.
According to a request to our mail system manufacturer, this is a desired behavior.
"The no-reply prefix is used to prevent loops between things such as autoresponders.
Loops can cause all sorts of problems and even blacklisting.
The number in the prefix is a variable so it not always the same nor can it be predicted.
I wonder if your gateway supports variables so you can whitelist a pattern:
no-reply=*@domain[.]com
Or may it supports regex."
Is there anything I can do to fix the problem?
Best Regards,
Jonas
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[edited by: Raphael Alganes at 11:02 AM (GMT -8) on 12 Dec 2024]